The feedthroughs, such as the HF or RF feedthroughs, are usually inserted in openings which are provided in the outside wall of the reaction chamber. It goes without saying that it is necessary for the feedthrough to be inserted in the respective opening in such a way that the reaction chamber remains sealed in a vacuum- and pressure-tight manner from the space outside.
The patent literature discloses a wide variety of embodiments of vacuum- and pressure-tight HF and RF feedthroughs. Furthermore, a wide variety of feedthroughs for vacuum recipients or the like are offered for sale by the relevant manufacturers.
However, with regard to the requirements stated below, as they arise specifically in the case of reaction chambers for the applications stated at the beginning, the known feedthroughs are not optimal, or make a compromise with respect to the overall set of requirements which follow:
1. HF feedthroughs should be insensitive to impact and shock, and especially not be made to leak by impact or shock, as may occur when working in reaction chambers.
2. HF feedthroughs should allow themselves to be cooled with water, especially whenever they are intended to conduct high levels of electrical energy into the interior space of the reaction chamber, without arc-overs to the chamber wall or other parts of the reaction chamber occurring.
3. HF feedthroughs should be easily exchangeable, allowing if need be defective parts to be easily replaced.
4. HF feedthroughs should also be suitable for being manufactured at low cost.